Improvement in metal-punching machines



JAMES R. LINDSAY, OF NEWARK, NEW JERSEY.

IMPROVEMENT IN METAL-PUNCHING MACHINES.

Specification forming part of Letters Patent No. 166,707, dated August17,1875; application filed June 16, 1875.

To all whom it may concern:

Be it known that I, JAMES R. LINDSAY, of Newark, Essex county, NewJersey, have invented an Improvement in Punching chines of the kind usedfor making tools, as hammers, swages, 870., of which the following is adescription:

Figure l is a side elevation of a press of the usual form, consisting ofbed A, standards B B, cap (J, cross-head D, and eccentric shaft E,actuated in any suitable manner. Upon the bed A it is customary to placea die or seat, as at H, upon which the bar of steel is laid when it ispunched, and having patented certain dies for forming the bodies of twohammers, or similar tools, at once, I have been led to devise thefollowing arrangements for holding the steel centrally on the seat andpunching two holes in the bar at once, at any desired distance apart. InFig. l, in connection with the die-seat, is shown a couple of shafts, aa, provided with crank-arms b b, and rotating in opposite directionsthrough the agency of two segments of gear, 0 c. A lever, cl, is furtherattached to one of the shafts, and connected by a link, 0, to a treadle,f. The shafts a extend from end to end of the die-seat, and are providedwith similar arms I) b at each end, all of which receive at theirextremities the ends of certain jaws v t, which lie upon the seat H, andcan be moved toward or from each other by pressure upon the treadle f. Aspring, 9, lifts the treadle to open the jaws z i. In the plan, Fig. 3,is shown another view of the cross-head D, shown inverted to display thearrangement of thetwo punches tt. The one at t is shown secured in thecross-head, while the other, t, is secured in a slide, Z, provided withany suitable means for adjusting the punch t toward or from the other,t. This arrangement makes it possible to set the punches at any desireddistance apart, although, to keep each punch at an equal distance fromthe edge of the cross-head, it would be necessary to provide both 1? andt with a slide, Z. I do not, however, find this necessary in practice.

The above arrangements greatly increase the ability of a press tooperate upon the material, for it will be seen that when the seat H isso adjusted beneath the punches that a hole is punched centrally in thewidth of an inch bar, it is adjusted for bars of all widths orthickness, as the jaws i t infallibly bring the center of the steelunder the punch, whatever its width. And as steel is seldom madeperfectly uniform, the liability to punch the hole out of center, whichoccurs with the use of a stationary gage, is entirely removed.

Having thus described my invention, what ,I claim, and desire to secureby Letters Patent, is-

1. The self-centering clamp for holding bars,

constructed with jaws '6 'i, in combination with cranks or arms b b,gears c c, and treadle or lever, substantially as herein shown anddescribed.

2. The combination, with the cross-head D, of the adjustable slide Z andpunches t t, substantially as herein shown and described.

3. The combination of the reciprocating cross-head, adjustable slide,punches, clamping devices, and lever, substantially as herein shown anddescribed.

JAMES R. LINDSAY.

Witnesses:

Tnos. S. CRANE, ALBERT G. TRUE.

